Metal girder



Feb. 2 1926. 1,571,240

C. DORNIER METAL GIRDER Original Filed Feb. 17, 1923 ezwenl ar:

Patented Feb. 2, 1926.

UNITED STA ES PATENT orncs.

GLAUDIUS OI FBIEDBI C JHSHAFEN-oN TflE-BoDENsiEE, GERMANY, I AS- SIGNOR OF ONE-HALF '10 FIRM DOBNIER METALLBAUTEN GESELLSCHAFT MI'I. BESGHRKNKTER HAFTUNG, OF FRIEDRICHSHAFEN-QN-THE-BODENSEE, GERMANY.

METAL GIRDER.

Original aliplication 'flled February 17, 1923, Serial No. 619,896. Divided and this application filed August To all wlwmz'tma z concern: I

Be it known that I, 'CLAUnIUs DoRNInn', a citizen of Germany, residing at Friedrichshafen-on-theBodensee, Germany, have invented certain new and useful Improvements in Metal Girders, of which the following is a specification.

My invention relates to metal girders and more especially toa metal girder intended for air craft construction, where structural elements of high strength and low weight. are required.

To this end I provide a box-shaped girder with oppositely located apertures having in wardly directed flangeswhich are connected with each other by means of tubular connecting pieces fixed to the flanges by riveting, welding or the like either at their inner 'or outer surface or at one end with the inner and at the other end with the outer surface a of the flange.

the planes of their longitudinal edges may be efl'ected in any desired manner, for in stance by means of-a panel. I prefer beInd-1 ing the marginal portionsof the side walls so as to form outwardly directed flanges and to connect these latter with each other by a sheet-metal strip which may be grooved or channelled.

In the drawings ailixed to this specificstion and forming part thereof, a girder embodying my invention illustrated in crosssection by way of exa ple.

Referring to the drawing, the girder consists of two side walls 1 and 2 provided with circular apertures 20 and 30, havin in wardly directed flanges 3 and 4 which are connected with each other by a short tubular piece 12 flanged at its ends, one flange 13 abutting against flange 4 of one aperture 1 from the inside, while the other flange 14 abuts against the flange 3 from the outside. The tubular piece 12 is fixed to the side walls by a circular row of rivets 1'5.

'17, 1825: Serial No. 50,874.

The marginal portions-of the side walls 1 and 2 are bent outwards at right angles. as shown at 16, and the parts 17 near the free edges of these portions are bent at an obtuse angle. To theparts 16 are riveted metal strips 10 and 11, the lower metal strip having two longitudinal grooves formed therein while the top metal strip 11 has the form of an ordinary channel.

The girder described combines low weight with extraordinary strength and rigidity and canfbe manufactured at comparatively very low costs. I

I wish it tobe understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled. in the art.

I claim 1.' A low weight sheet-metal girder for g 1 air craft'constru'ction comprising two juxta- The connection ofthe two sidewalls .m'

posed apertures.

2. A low weightsheet-metal girder for air craft construction comprisingtwo juxtaposed apertured side walls, inwardly directed flanges adjoining the apertures of said walls and a flanged tubular connecting piece rigidly fixed between the flanges of oppositely disposed apertures.

3. A low weight sheet-metal girder'for air craft construction comprising, two juxtaposed apertured side walls, inwardly direct ed flanges adjoining the apertures of. said walls, a flanged tubular connecting piece rigidly fixed between the flanges of oppositely disposed a ertures and grooved sheet metal strips fixe to and connecting adjoining longitudinal edges of said side walls.

' In testimony whereof I aflix my signature.

QLAUDIUS- DORNIER. 

